RM0090: Reference manual - STMicroelectronics

RM0090 Embedded Flash memory interface
3.8.2 Flash key register (FLASH_KEYR)
The Flash key register is used to allow access to the Flash control register and so, to allow
program and erase operations.
Address offset: 0x04
Reset value: 0x0000 0000
Access: no wait state, word access
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
KEY[31:16]
w w w w w w w w w w w w w w w w
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
KEY[15:0]
w w w w w w w w w w w w w w w w
Bits 31:0 FKEYR: FPEC key
The following values must be programmed consecutively to unlock the FLASH_CR register
and allow programming/erasing it:
a) KEY1 = 0x45670123
b) KEY2 = 0xCDEF89AB
3.8.3 Flash option key register (FLASH_OPTKEYR)
The Flash option key register is used to allow program and erase operations in the user
configuration sector.
Address offset: 0x08
Reset value: 0x0000 0000
Access: no wait state, word access
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
OPTKEYR[31:16
w w w w w w w w w w w w w w w w
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
OPTKEYR[15:0]
w w w w w w w w w w w w w w w w
Bits 31:0 OPTKEYR: Option byte key
The following values must be programmed consecutively to unlock the FLASH_OPTCR
register and allow programming it:
a) OPTKEY1 = 0x08192A3B
b) OPTKEY2 = 0x4C5D6E7F
Doc ID 018909 Rev 3 78/1416